Hi Henry:

I have an Inmarsat demodulator working for the lower speed control channels.  I 
am writing a program to decode the traffic, but this is not a trivial task.  
Think on the order of 1000 lines of C.  It is "almost" working, I am hoping for 
valid output in the next week or so, depending on my free time.

My program is currently a standalone program, but once it's done it could 
conceivably be converted to one or more gnuradio blocks.  

I suggest the following document to give you background on the channel 
specifications for Inmarsat:

http://www.icao.int/safety/acp/inactive%20working%20groups%20library/acp-wg-m-iridium-8/ird-swg08-wp07%20-%20old_amss_material_ch.4_plus_attachment.doc

The demodulation is fairly easy, read the spec document and the channel 
characteristics are pretty well described.  My gnuradio demodulator is based on 
the GMSK demod block.  I'm using a home brew patch antenna, and the LNA4ALL low 
noise amplifier.

Kevin

Sent from my iPad

> On May 3, 2016, at 12:45 PM, Henry Barton <[email protected]> wrote:
> 
> http://rtlsdrblog.rtlsdrblog.netdna-cdn.com/wp-content/uploads/2015/10/sdrplay_lband-1024x573.png
> I didn’t see the widest signal (bright yellow) from this picture on 
> sigidwiki.com. Does anyone know what it is? If so, can it be decoded by 
> GNUradio? Thanks.
> _______________________________________________
> Discuss-gnuradio mailing list
> [email protected]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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